Extremely small particles of pollution have the potential to evade the lungs' protective filter system and end up deep in the body, scientists suggest.

Researchers speculate the particles could then build up in blood vessels and raise the risk of heart disease.

They say their early study - based on extremely small particles of gold - brings them a step closer to cracking the "mystery" of how air pollution and heart disease and stroke are linked.

The work appears in ACS Nano.'Missing link'

Air pollution is estimated to help shorten of the lives of about 40,000 people a year in the UK.

Several studies suggest it does this in the most part by worsening or triggering heart or lung problems.

But despite many theories, exactly how air pollution affects the heart is not fully understood.

Some scientists suspect that it may be partly down to extremely tiny pollution particles (known as nanoparticles) that could potentially be too small to be removed by the body's filter system in the nose and lungs.

To investigate researchers, from the University of Edinburgh and universities in the Netherlands studied extremely small particles of inert gold - at a similar size to those found in diesel exhaust fumes.

Scientists asked 14 healthy volunteers to breathe in air containing pieces of gold, which scientists consider inert, while exercising for two hours.

A day later, researchers found that gold nanoparticles had made their way into the bloodstream of most participants.

And for some people, the particles remained in the body for months - they were detected in people's urine three months later.

Scientists suggest this shows that nanoparticles of pollution have the potential to make a similar journey into the body.

Dr Nicholas Mills, co-author of the work, said: "We have always suspected that nanoparticles in the air that we breathe in could escape from the lungs and enter the body, but until now there was no proof.

"These findings are of wide importance for human health, and we must now focus our attention on reducing emissions and exposure to airborne nanoparticles."

In another similar experiment, researchers asked three patients with clogged-up blood vessels to breathe in air containing tiny gold nanoparticles.

A day later, when the patients had part of their damaged blood vessels surgically removed, there was evidence of this gold building up in the diseased parts of vessels.

Researchers speculate that by accumulating in vulnerable areas of the body air pollution particles could worsen heart disease and stroke.

Dr Zongbo Shi, at the University of Birmingham, said: "This is a well designed and high quality study, and the results unequivocally showed that nanoparticles can travel from lungs to blood vessels and different organs.

"This research provides a missing link or mechanism between airborne nanoparticles exposure and their adverse health effects. "

But Prof Peter Dobson, at the University of Oxford, argues the study has a number of pitfalls, including the fact that gold does not match the chemistry of particles present in pollution.

And Mike Hawes of the Society of Motor Manufacturers and Traders said the industry had invested billions into reducing emissions and had drastically reduced or banished pollutants such as particulates.

Meanwhile Prof Jeremy Pearson, at the British Heart Foundation, which part-funded the study, said there was no doubt that air pollution was a killer that needed to be taken seriously.

But he cautioned more research was still needed to pin down the mechanism involved and firm up the evidence.

Toxic diesel particles penetrate right through to the heart, scientists warn

By Henry Bodkin 26 April 2017 • 1:04pm

Toxic particles from diesel vehicles can work their way through the lungs and into the bloodstream, raising the risk of heart attacks and strokes, researchers have proved for the first time.

The nanoparticles, which cannot be traced by Government measuring equipment, stay in the body for months and tend to build up in areas that are most prone to disease.

Scientists have long known that air pollution is bad for the lungs, but until now they did not know whether exhaust particles were able to penetrate further into the body.

A team at Edinburgh University used harmless gold nanoparticles, at an equivalent size to diesel, in a human experiment that simulated cycling through a city.

By looking at surgically removed body samples they found that the gold had accumulated in the fatty areas inside blood vessels that are responsible for heart attack and strokes.

This tallies with previous research showing that cardiovascular disease, of which stroke is a form, accounts for 80 per cent of the roughly 50,000 premature deaths from air pollution each year in the UK.

The scientists say the findings are particularly worrying as officials only have the capacity to measure the overall volume of pollution particles in the air, rather than their number.

While the overall volume of pollution has been falling, they say the number of the most toxic tiny particles able to get deep inside the body is on the rise.

Diesel engines emit 50 times more of the nanoparticles than petrol engines Credit: Chris Ratcliff

Dr Nicholas Mills, Professor of Cardiology at Edinburgh and one of the study’s co-authors, said: “We have always suspected that nanoparticles in the air that we breath could escape from the lung and enter the body, but until now there was no proof.

“These findings are of wide importance for human health, and we must now focus our attention on reducing emissions and exposure to airborne nanoparticles.”

While petrol particles are also able to penetrate the lungs, a petrol engine will throw out roughly 50 times fewer particles than a diesel engine of equivalent size, the researchers said.

The particles are also capable of penetrating the masks worn by some cyclists to avoid pollution.

Dr Mark Miller, who led the Edinburgh study, said: “It is striking that particles in the air we breathe can get into our blood where they can be carried to different organs of the body.

“Only a very small proportion of inhaled particles will do this, however, if reactive particles like those in air pollution then reach susceptible areas of the body then even this small number of particles might have serious consequences.”

It is possible to fit filters onto diesel vehicles to reduce the number of particles they emit, however these can make cars and lorries inefficient, burning more fuel overall, as well as more expensive.

The research team said a mandatory imposition of filters on all vehicles was premature.

• The Surgeon General has determined that there is no safe level of exposure to ambient smoke!

• If you smell even a subtle odor of smoke, you are being exposed to poisonous and carcinogenic chemical compounds!

• Even a brief exposure to smoke raises blood pressure, (no matter what your state of health) and can cause blood clotting, stroke, or heart attack in vulnerable people. Even children experience elevated blood pressure when exposed to smoke!

• Since smoke drastically weakens the lungs' immune system, avoiding smoke is one of the best ways to prevent colds, flu, bronchitis, or risk of an even more serious respiratory illness, such as pneumonia or tuberculosis! Does your child have the flu? Chances are they have been exposed to ambient smoke!